Ribollita

Steps

1. 1
   Drain the soaked beans, cover them with the water in a pot, add the rosemary and simmer for 1 hour until tender, salting them only at the end. Remove the rosemary and keep the cooking water.
2. 2
   Purée half the beans with a little of their cooking water; leave the rest whole.
3. 3
   Heat 4 tbsp of the olive oil in a large pot over medium heat and cook the onion, carrots and celery slowly for 10 minutes until soft, then add the garlic for 1 minute.
4. 4
   Add the tomatoes and cook 5 minutes, then the cavolo nero and cabbage, stirring until they wilt.
5. 5
   Add the bean purée, the whole beans and enough of the cooking water to cover everything well, about 1.2 litres. Season and simmer, covered, for 1 hour.
6. 6
   Push the bread down into the soup and simmer 10 minutes more, stirring, until it breaks down and the soup is very thick.
7. 7
   Let it cool, then refrigerate overnight — the rest is the point of the dish.
8. 8
   The next day reheat it slowly in a heavy pan, without stirring too often, until a light crust forms on the bottom, then fold the crust in.
9. 9
   Serve with the raw red onion and the remaining olive oil poured generously over each bowl.